I just found a download for AMD APP SDK OpenCL version 2.4 to 2.9 but I read in the descriptif of PDF, none support this HD 7790 aparently... And after the version 2.6, Windows XP is no more supported (OpenCL setup no show in the menu)...

I need it because I want to accelerate a plugin NeatVideo and I don't need to buy/use Windows 7 because everything I do in WindowsXP, I can do it with Windows 7butI gainnothing on thermof quality andperformance, I just lost+/-200euros...